KT100 case: CAD model (updated 6-21-2021)

Pete_Muller

Moderator
Has anyone modeled one/some/all parts of any 2-cycle kart engines?

Sometime around 15-20 years ago, I modeled a set of Yamaha cases (a few screen grabs below). These were modeled and rendered in Ashlar Cobalt. I have the original CAD models on a hard drive somewhere, and could export them as STEP, etc., if anyone is interested.

PM


KT100_trans1.jpg


kt100_22s.jpg


kt100_21s.jpg
 
Now im curious . This drawing a few dimensions and a datam line or two .
Could a skilled cnc preson duplicate this ?
 
flattop,

Yes, though no fins in my model. Everything else is on the money -- or let's say: dimensions pulled off a brand new KT100 case. Some dimensions that were obviously intended by Yamaha to be *on* a whole millimeter number but may have been .05mm off (or something like that), I corrected to the exact value in my model.
Looking at the top rendering, I'm not positive that I have the two mounting points for the coil in there, but I could easily add that in. The case screws, bottom and top stud holes, and alignment pin holes are definitely in.

I'll dig into my files tonight and find this, and then get it loaded into my current CAD program (Fusion 360) so I can provide a bit more info.

PM
 
flattop,

Yes, though no fins in my model. Everything else is on the money -- or let's say: dimensions pulled off a brand new KT100 case. Some dimensions that were obviously intended by Yamaha to be *on* a whole millimeter number but may have been .05mm off (or something like that), I corrected to the exact value in my model.
Looking at the top rendering, I'm not positive that I have the two mounting points for the coil in there, but I could easily add that in. The case screws, bottom and top stud holes, and alignment pin holes are definitely in.

I'll dig into my files tonight and find this, and then get it loaded into my current CAD program (Fusion 360) so I can provide a bit more info.

PM
If you're willing to share I'd be curious to dissect the parts and see if I could make a 3D printed version of it :)
The g/f went back to school so we have access to all of Autodesk's products for free :D lol
 
Follow up: I found the hard drive that appears to contain most of the CAD models I ever created for work or just entertainment (solid models going back ~20 years or so, and cad drawings back to the early or mid 90s, yikes!). Some time tomorrow I'll get the ones of interest converted into a modern format that can be worked with.

PM
 
Follow up: I found the hard drive that appears to contain most of the CAD models I ever created for work or just entertainment (solid models going back ~20 years or so, and cad drawings back to the early or mid 90s, yikes!). Some time tomorrow I'll get the ones of interest converted into a modern format that can be worked with.

PM
I can work with your old cad files! They're still .dwg file formats! :) So you don't need to convert anything for me. As far as Solidworks goes, you can export to .dwg as well with those.
I'd be really curious the kinds of things you came up with :D
 
Mac_49 (and others).

Here is a link to grab two cad files: the ignition side and PTO side of a Yamaha KT100 case (one zip file): https://www.dropbox.com/s/54tur9kdw9r7igi/KT100_case.zip?dl=0

It was interesting going back and looking at this since I modeled this over 16 years ago. Dimensionally, I'm confident that all bolt hole positions and diameters are correct. The ignition-side casting (under the ignition cover) is not yet "finished", and there are no cooling fins in the outside of the case.

For those with interest: I originally modeled these parts in Ashlar Cobalt. To convert, I exported the models as STEP files, imported the models into Fusion 360 (my current Cad/Cam program). At that point I had to scale down the parts by 25.4/1 (most likely because Cobalt is using a 16+ year old export format that doesn't handle metric/imperial correctly during export). Once scaled in Fusion 360, I re-exported as modern STEP files (which generally seems to be one of the best methods for trading solid models between Cad programs).

Now that these parts are in a current gen program, I can capture the design history which will be very handy. I can also export into many different formats if anyone wants something different and/or has difficulty with the STEP files. As I work on this, I'll re-upload the model with any changes/additions I make.

Modifications, suggestions, criticisms all welcome. (y)

PM



Screen Shot 2021-06-18 at 7.46.20 AM.jpg
 
Width of just the case? Or including the crank? Other?

My CAD model measures 116.5mm outside to outside on the assembled case.

PM
 
Need the overall width without a clutch...from the tip of the crank on one side to whatever sticks out the most on the other side...Please.
My Honda GS 190 engine is 14.5" and I am looking for something that is narrower.
Thank You
 
From tip of crank to ignition side cover 8".
With Horstman DXL and 3rd bearing about 9 1/2".
With Horstman Steel Nytro and 3rd bearing about 10 1/2".
 
Need another dimension please...what is the height of the KT100 without an engine mount?

By height, I mean the bottom of the case (no mount) to whatever sticks up the highest...whether it is the spark plug boot or the cylinder head.

Thank You!
 
Need another dimension please...what is the height of the KT100 without an engine mount?

By height, I mean the bottom of the case (no mount) to whatever sticks up the highest...whether it is the spark plug boot or the cylinder head.

Thank You!
12" to top of spark plug, add 1/2" for boot depending on which boot you use. I have two 3rd bearing mounts, one is 1/2" thick for the DXL clutch and the other one is 3/4" thick for the Steel Nytro clutch. Both these motors have a Burris motor mount #BMC 592. With motor mount and 3rd bearing the DXL clutch motor is 13 1/2" tall and motor mount and 3rd bearing for the Steel Nytro clutch is 14" tall, both are to the top of boot.
 
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